Re: [ihc] Age Old Carb Questions

["Joseph Shaw, II" <josephshaw@xxxxxxxxxxxxx>]

Allan-

Thanks for the advice-I did check the order of the plugs last night, as well
as only changing the wires one at a time which should have insured that they
would run at least as well as before my work!  I tested the diaphragm while
it (the dist) was out by sucking on the line.  It seemed to work
fine-including holding its pressure while I held my breath with the tube in
my mouth.  I also checked and lubed the mechanical advance weights while I
had the dist out.  The "ported vacuum"-does that mean that if I suck lightly
on the vacuum line to the carb, I should not get anything coming through?
It should only open at oressure/higher rpm's?  I can't really currently
check the timing advance at rpm, as I can not keep it running long enough to
do so.  The shaft was not wobbly-felt VERY slight "give" in it while trying
to wiggle with my fingers, but not enough to see-or really feel except I
could feel it hit an edge almost as soon as I tried to wobble-if that makes
sense.  I have had a "wobbly" dist before, but it had considerably
more "wobble" than this one-I have had several well-working IH's that had
dist's that I could feel this minor amount of "give" in.

My next attempt may be to install an older style Holley on it that I am
pretty sure is still good and see if it runs better with that one on it.  I
don't know all the details, but think I can mount the older style on there
if I adjust all the linkage settings to work.

One other issue I noticed-it seems as though nothing ever depresses the
accelerator pump on this one.  The rod is going into one of the slots meant
to receive it up front, but upon complete depression of the throttle, the
acc pump does not move-the linkage just slides in the slot.  I have not
touched or adjusted the carb sicen I started tinkering, so don't know why
this would cause a problem now, and not before, but it seemed odd to me-the
carb is still pumping in some fuel when I pull on the throttle, but the acc
pump mechanism does not move at all.  Does that make any sense?

Thanks again for the help-you have answered just about every question I have
had on this topic, and I appreciate it!  Coffee or not, you have been a BIG
help!

Michael

----- Original Message -----
From: "Allan Ericson" <lowvolt@domain.elided>
To: <ihc@domain.elided>
Sent: Wednesday, October 01, 2003 7:13 AM
Subject: Re: [ihc] Age Old Carb Questions


> Michael-
>
> Check to see that the plugs are all in the right order.
>
> Check to see that the timing is advancing with rpm, and that it's stable.
A
> wobbly shaft or defective vacuum advance can cause instability.
>
> Check to see that the vacuum advance is working properly, which includes
the
> timing staying put. Sometimes the diaphragm cracks, which makes the timing
> advance and then retard, which results in a rough run.
>
> Make sure the ported vacuum is really ported. No vacuum at idle is proper.
>
> Backfire from the carb is usually caused by the timing being too far
> advanced, although crossfiring or miswired plugs can do the same thing.
>
> I left a few things out, but I can't remember what they are. Must have
> coffee, must have coffee, must.....
>
> ----- Original Message -----
> From: "Joseph Shaw, II" <josephshaw@domain.elided>
> To: <ihc@domain.elided>
> Sent: Wednesday, October 01, 2003 5:13 AM
> Subject: [ihc] Age Old Carb Questions
>
>
> > Okay, regarding my recent acquaition '75 Scout II (345, Auto, 2WD), I
have
> > re-timed, installed a new fuel pump, new plugs and wires, etc.  However,
> since
> > installing the new fuel pump, and thinking, NOW I likely have it
working,
> I
> > should REALLY do it right, and thus, RE-setting the air gap, trying to
> time
> > it, etc, it is not running as well as I had it running at some points
> before.
> > It WILL start on its own now, which it wasn't doing before (needed a
> little
> > priming), but runs rougher, lots of small sputters and backfires through
> the
> > carb, etc.  I have tweaked the timing a million times, in each
direction,
> and
> > have not been able to make it better, and it is not quite running well
> enough
> > to get out and check the timing with the light to make SURE of where it
> needs
> > to go before I try something else-here is my current thinking-wondering
> what
> > anyone thinks of this:
> >
> > I did notice that when disconnecting the vacuum line from the carb base
to
> the
> > dist that it was fairly loose, with enlarged ends.  It has come off of
its
> own
> > accord since this process began.  Thus, I am replacing that vacuum line
> today,
> > but could a small vacuum line from that port cause such a reaction?
> >
> > Just curious-it didn't sputter this bad or run this poorly when I had
the
> > vacuum line disconnected to time it before, so don't see why it should
run
> > that bad with partial vcacuum either.
> >
> > Thanks for any input-I'll let you know how it turns out!
> >
> > And for the record-I DO know the whole timing procedure from scratch,
but
> > since I had it running failr well before, and could see/hear how the
> timing
> > affected it, I KNOW that it is within the timing general area-HATE to go
> to
> > all of that work (no one around to help with turning it over while I
feel
> for
> > vacuum or pressure, etc) when I am quite confident it doesn't need that
> > specific of a re-time.
> >
> > Michael